Sometimes search query generation fails to identify the most discriminative terms to use as required terms. Part of the reason is that the required terms are determined without regard to which terms the syntactic structure indicates are important.
Current search query generation methods only include terms identified with taxonomies such as the Hierarchical Unified Type Taxonomy (HUTT) types as required terms. This can lead to bad search results in cases where the HUTT terms are not good discriminators across all documents in a corpus.